1. Field of the Invention
The present invention relates to a reciprocating compressor used for vehicle air-conditioning, and the like.
2. Description of the Related Art
Swash plate type reciprocating compressors used as compressors for vehicle air-conditioning, and the like are conventionally known. A swash plate type reciprocating compressor generally comprises a cylinder assembly formed from a front side cylinder block and a rear side cylinder block joined one to another. A plurality of cylinder bores are provided in the area around the center axis of the cylinder assembly, so as to pass therethrough between the front and rear end faces. Double-headed pistons are provided so as to be slidable within the cylinder bores. Also, a drive shaft is rotatably supported at the center axis of the cylinder assembly, this drive shaft being provided with a cam plate (a swash plate in this case) as a means for converting the rotational motion of the drive shaft into linear motion. The double-headed pistons are fitted to the cam plate via shoes, thus constructing an apparatus in which the rotation of the drive shaft causes the reciprocating movement of the double-headed pistons within the cylinder bores, thereby compressing a refrigerant gas in the cylinder bores.
Also, with such swash plate compressors, a cylinder cover having a discharge chamber and suction chamber therein is provided at either end of the cylinder assembly, and a valve plate is provided between the cylinder cover and cylinder assembly. Further, a plurality of suction ports are bored to link the cylinder bores and the suction chamber, and a plurality of discharge ports are bored to link the cylinder bores and the discharge chamber. Also, suction valve forming plate with integrally formed suction valves for controlling the opening and closing of each suction port is provided between the valve plate and the cylinder assembly, and a discharge valve forming plate with integrally formed reed-type discharge valves for controlling the opening and closing of each discharge port is provided between the valve plate and the cylinder cover.
Here, since the reed-type discharge valves for such swash plate type compressors are formed of thin metal plates, in the event that the plates are excessively bent due to the pressure of the refrigerant gas being discharged from the discharge ports, the valves may be permanently warped. Accordingly, a metal retainer plate with integrally formed retainers and a gasket for sealing each chamber is conventionally introduced between the discharge valve forming plate and cylinder cover to restrict the degree of opening of each reed-type discharge valve. Further, the retainers have a slanted portion which gently rises from the base surface of the retainer plate at an angle generally approximating the angle of the reed-type valve when opened, and the degree of opening of the reed-type discharge valve is restricted within this slanted portion.
However, there have been cases of the base portion of the slanted pieces bending due to great discharge pressure when there is a overload due to liquid compression and the like acting on the aforementioned slanted pieces either via the discharge valves or directly. Also, in the event that the base portion of the slanted piece is greatly bent, there is the possibility that the degree of opening of the reed-type discharge valves cannot be restricted to the predetermined level.